Injection molding flow control apparatus and method

ABSTRACT

Injection molding apparatuses and methods wherein a valve pin is controllably driven upstream and downstream along an axis between a first closed position where the tip end of the valve pin obstructs the gate to prevent the injection fluid from flowing into the cavity, a full open position and one or more intermediate positions,
         wherein the valve pin is drivable to be disposed or held in a selected intermediate position for a selected period of time during the course of an injection cycle where the tip end of the valve pin restricts flow of injection fluid through the gate to the mold cavity.

BACKGROUND

Injection molding systems have been developed having flow controlmechanisms (e.g., a controller) that control the movement and/or rate ofmovement of a valve pin over the course of an injection cycle to causethe pin to move to one or select positions and/or to control the rate ofmovement of the pin over the course of the injection cycle. In oneembodiment, the pin movement is controlled in order to raise or lowerthe rate of flow of fluid material to correspond to a predeterminedprofile of fluid flow rates for the injection cycle. A sensor istypically provided that senses a condition of the fluid material or ofthe apparatus (such as pin position) and sends a signal indicative ofthe sensed condition to a program contained in a controller that usesthe signal as a variable input to control movement of the valve pin inaccordance with the predetermined profile.

SUMMARY OF THE INVENTION

The present invention relates to the storage and transmission of recipedata (process parameters) for the molding of articles in an injectionmolding machine. A controller includes a flow control microcontroller(MCU) that receives recipe data from a recipe storage microcontroller(MCU) mounted to a mold of an injection molding machine, the recipestorage MCU storing the recipe data defining process parameters for themolding of articles in the mold. The flow control MCU executesinstructions for controlling pin motions in the mold according to therecipe data. In one embodiment, a human operator interface is providedfor transmitting data to and/or from at least one of the recipe storageand flow control MCU's, allowing the operator to monitor, modify and/orcontrol the process parameters during a molding cycle and/or to create amodified or new recipe for subsequent storage on the recipe storage MCU.

In accordance with one embodiment of the invention, a system is providedcomprising a recipe storage microcontroller (MCU) mounted to a mold ofan injection molding machine and storing recipe data defining processparameters for molding articles in the mold, wherein the recipe dataincludes one or more profiles of data representative of events orconditions during or over corresponding injection cycles that controloperation of one or more valve pins to control the rate of flow ofinjection material to the mold over the course of the injection cycles,

a flow controller, including a flow control microcontroller (MCU),remote from the mold and operative to receive the recipe data andexecute instructions for controlling valve pin motion(s) according tothe recipe data; anda human operator interface remote from the mold and either remote-fromor local-to the controller for transmitting recipe data to and/or fromat least one of the recipe storage and flow control MCUs;wherein each MCU is a single chip microcontroller.

In one embodiment, the system includes a first communication channelbetween the human operator interface and controller, and a secondcommunication channel between the recipe storage MCU and the controller.

In another embodiment, the flow control MCU is mounted on a circuitboard mounted on the injection molding machine.

In another embodiment, the recipe storage MCU is mounted on a circuitboard mounted on the mold.

In another embodiment, the system includes a display.

In another embodiment, the display is mounted on the injection moldingmachine and includes one or more parameters relating to valve pinmotion(s).

In another embodiment, the recipe storage MCU is mounted in a junctionbox and the junction box transmits signals between the mold and the flowcontrol MCU for controlling the valve pin motion(s).

In another embodiment, the profile comprises a profile of one or more ofvalve pin position, pressure of an injection material, temperature of aninjection material or position of another operational component of thesystem.

In another embodiment, the human operator interface is a voice activatedinterface.

In another embodiment, the human operator interface is a wirelessinterface.

In another embodiment, the human operator interface is a wiredinterface.

In another embodiment, the flow control MCU controls the motions of aplurality of valve pins.

In another embodiment, the system includes a plurality of flow controlMCUs each controlling a corresponding one of a plurality of pins.

In another embodiment, the flow control MCU is mounted on a hydraulicpower unit.

In one embodiment, at least one flow control MCU, receives, displaysand/or records a signal from an electronic mold counting sensor forcorrelating detected pin motion data to the recipe data during a givenmolding cycle.

In accordance with one embodiment of the invention, a system is providedcomprising a recipe storage microcontroller (MCU) storing recipe datadefining process parameters for molding articles in a mold, and a flowcontroller including a flow control MCU, both the recipe storage MCU andthe flow control MCU being mounted to the mold;

the recipe data including one or more profiles of data representative ofone or more events or conditions during or over corresponding injectioncycles that control operation of one or more valve pins to control therate of flow of injection material to the mold over the course of theinjection cycles;the flow control MCU being operative to receive the recipe data andexecute instructions for controlling valve pin motion(s) in the moldaccording to the recipe data; anda human operator interface remote from the mold for transmitting recipedata to and/or from at least one of the MCUs;wherein each MCU is a single chip data microcontroller.

In one embodiment, the recipe data includes a rate of pin movement.

In another embodiment, the recipe data includes a pressure profile for amolding cycle.

In another embodiment, the flow control MCU generates signals for anelectric motor for controlling one or more of pin position and rate ofpin movement.

In accordance with one embodiment of the invention, a method is providedcomprising electronically transmitting a recipe of data from a humanoperator interface to a recipe storage system mounted on a mold of aninjection molding machine, the recipe storage system including a recipestorage microcontroller (MCU) for storing the recipe, wherein the recipedata includes one or more profiles of data representative of one or moreevents or conditions during or over corresponding injection cycles thatcontrol operation of one or more valve pins to control the rate of flowof injection material to the mold over the course of the injectioncycles;

a controller, remote from the mold, including a flow control MCUexecuting computer instructions to control the valve pin motion(s)during a process of molding part(s) in the mold in accordance with therecipe,electronically transmitting feedback concerning the molding processand/or the molded part(s) to the operator interface; andelectronically transmitting a modified recipe from the operatorinterface to the recipe storage system for a subsequent process ofmolding parts.

In accordance with one embodiment of the invention, a method is providedcomprising transmitting, from a mold MCU mounted on a mold of aninjection molding machine to a flow control MCU remote from the mold, arecipe of data defining process parameters for molding articles in themold, wherein the recipe data includes one or more profiles of datarepresentative of one or more events or conditions during or overcorresponding injection cycles that control operation of one or morevalve pins to control the rate of flow of injection material to the moldover the course of the injection cycles; transmitting signals from theflow control MCU to an actuating system that controls the molding ofarticles in the mold according to the recipe;

operating the actuating system according to the signals to producearticles in the mold.

In another embodiment, the method includes transmitting feedbacksignals, from the actuating system, the mold and/or a manifold mountedto the machine, to the flow control MCU concerning the molding processand/or the molded parts.

In another embodiment, the method includes receiving, at the mold MCU, amodified recipe based on the feedback signals.

In another embodiment, the method includes transmitting, from the moldMCU to the flow control MCU, the modified recipe.

In one embodiment, the method includes transmitting signals from theflow control MCU to the actuating system to control the molding ofarticles in the mold according to the modified recipe.

In one embodiment, the method includes removing the mold from themachine and inserting a new mold, the new mold including as the recipe anew mold recipe stored on the new mold MCU prior to the inserting step.

In one embodiment, the method includes transmitting the new mold recipefrom the new mold MCU to the flow control MCU.

In one embodiment, the method includes transmitting signals from theflow control MCU to the actuating system to control the molding ofarticles in the mold according to the new mold recipe.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and further advantages of the invention may be betterunderstood by referring to the following description in conjunction withthe accompanying drawings in which:

FIG. 1 is a schematic of one embodiment of the invention utilizingmicrocontrollers (MCUs) for monitoring and/or controlling an injectionmolding process, the system including a recipe MCU located at the moldand a flow control MCU preferably remote from (optionally local to) themold, and various human operator interfaces remote from the mold formonitoring and/or providing input to the MCUs with regard to theinjection molding process;

FIG. 2 is a flow chart illustrating one method embodiment of theinvention;

FIG. 3 is a flow chart illustrating another method embodiment of theinvention;

FIG. 4 is a flow chart illustrating another method embodiment of theinvention;

FIG. 5 is a flow chart illustrating another method embodiment of theinvention;

FIG. 6 is a schematic of one embodiment of an injection moldingapparatus utilizing the invention during an injection molding cycle,namely a recipe (of process parameters) stored on a recipe storagesystem mounted in a mold is transmitted to and executed by a controller,the molding apparatus including a pair of sequential gates with a firstgate entering a center portion of a mold cavity having been opened andnow closed such that a first shot of fluid material has entered thecavity and traveled past the positions of a pair of second sequentialgates (one at each end of the mold cavity), each second gate being openwith its valve pin having traveled along an upstream restricted flowpath RP allowing a second sequential shot of fluid material to flow intoand merge with the first shot of material within the cavity;

FIGS. 6A-6E are schematic cross-sectional close-up views of the centerand one of the lateral gates of the FIG. 6 apparatus showing variousstages of the progress of injection;

FIG. 7 is a schematic of one embodiment of a hydraulically actuatedvalve pin in which at least one port of an actuator is connected to aflow restrictor so as to restrict the flow of hydraulic drive fluid andslow the opening of the valve pin by a selected lessening of pin openingvelocity by use of a controller interconnected to the flow restrictor,the controller enabling the user to select a percentage of predeterminedfull open position velocity that the hydraulic drive supply to theactuator normally operates at full open velocity drive fluid pressure;

FIGS. 7A, 7B are schematic cross-sectional views of the hydraulic valvesand restrictors used in the system of FIG. 6;

FIGS. 8A, 8B show various embodiments of piston sensors that can be usedin a variety of implementations of the invention, the sensors shown inthese figures being mounted so as to measure the position of the pistoncomponent of the actuator which is indicative of the position of thevalve pin relative to the gate;

FIGS. 8C, 8D show embodiments using limit switches that detect andsignal specific positions of the actuator that can be used to determinevelocity, position and switchover to higher openness of valve restrictorand/or upstream velocity of travel of the actuator and valve pin;

FIGS. 9A-9D are a series of graphs representing actual pressure (versustarget pressure) measured in four injection nozzles coupled to amanifold, such as in the apparatus of FIG. 6; and

FIG. 10 shows an interactive screen display of a user interface, such asthat shown in FIG. 1, which screen is used to display, create, edit andstore target profiles.

DETAILED DESCRIPTION

Various embodiments of the present invention are now described withreference to the drawings. In the following description, for purposes ofexplanation, numerous specific details are set forth in order to providea thorough understanding of one or more implementations of the presentinvention. It will be evident, however, that the present invention maybe practiced without these specific details. In other instances,well-known structures and devices are shown in block diagram form inorder to facilitate describing the present invention.

As used in this application with regard to various monitoring andcontrol systems, the terms “component” and “system” are intended torefer to a computer-related entity, either hardware, a combination ofhardware and software, software, or software in execution. For example,a component may be, but is not limited to being, a process running on aprocessor, a processor, an object, an executable, a thread of execution,a program, and/or a computer. By way of illustration, both anapplication running on a server and the server can be a component. Oneor more components may reside within a process and/or thread ofexecution and a component may be localized on one computer and/ordistributed between two or more computers.

The present invention may also be illustrated as a flow chart of aprocess of the invention. While, for the purposes of simplicity ofexplanation, the one or more methodologies shown in the form of a flowchart are described as a series of acts, it is to be understood andappreciated that the present invention is not limited by the order ofacts, as some acts may, in accordance with the present invention, occurin a different order and/or concurrent with other acts from that shownand described herein. For example, those skilled in the art willunderstand and appreciate that a methodology could alternatively berepresented as a series of interrelated states or events, such as in astate diagram. Moreover, not all illustrated acts may be required toimplement a methodology in accordance with the present invention.

In various embodiments of the invention disclosed herein, the term“data” is used. Data means any sequence of symbols (typically denoted“0” and “1”) that can be input into a computer, stored and processedthere, or transmitted to another computer. As used herein, data includesmetadata, a description of other data. Data written to storage may bedata elements of the same size, or data elements of variable sizes. Someexamples of data include information, program code, program state,program data, other data, and the like.

As used herein, computer storage media includes both volatile andnon-volatile, removable and non-removable media for storage ofinformation such as computer-readable instructions, data structures,program modules, or other data. Computer storage media includes RAM,ROM, EEPROM, FLASH memory or other memory technology, CD-ROM, digitalversatile disc (DVDs) or other optical disk storage, magnetic cassettes,magnetic tape, magnetic disk storage or other magnetic storage devices,or any other medium which can be used to store desired information andwhich can be accessed by the computer.

The methods described below may be implemented in a suitable computingand storage environment, e.g., in the context of computer-executableinstructions that may run on one or more processors, microcontrollers orother computers. In a distributed computing environment (for example)certain tasks are performed by remote processing devices that are linkedthrough a communications network and program modules may be located inboth local and remote memory storage devices. The communications networkmay include a global area network, e.g., the Internet, a local areanetwork, a wide area network or other computer network. It will beappreciated that the network connections described herein are exemplaryand other means of establishing communications between the computers maybe used.

A computer may include one or more processors and memory, e.g., aprocessing unit, a system memory, and system bus, wherein the system buscouples the system components including, but not limited to, the systemmemory and the processing unit. A computer may further include diskdrives and interfaces to external components. A variety ofcomputer-readable media can be accessed by the computer and includesboth volatile and nonvolatile media, removable and nonremovable media. Acomputer may include various user interface devices including a displayscreen, touch screen, keyboard or mouse.

A microcontroller (MCU) is used in the present invention to control someor all of the functions of an electronic device or system. An MCU is asmall self-contained computer chip, essentially comprising a smallcomputer on a single integrated circuit and including a microprocessor,memory, and I/O on a single chip. The chip may be programmed for selectfunctions, the program code being stored on Flash, EPROM or othernon-violate memory. An MCU is used in each of a recipe storage system, aflow control system, and a user interface system in the embodimentdescribed below. The MCU may be embedded in a printed circuit board(PCB), e.g., within the main PCB of the controller, a PCB within astorage device (in a junction box) and/or a PCB within an input device(such as a voice input interface). In contrast, PLC's (programmablelogical controllers) are costly and not as effective (too slow and/oroffer limited functionality).

Flow Control Apparatus and Method

FIG. 1 is a schematic diagram of a flow control apparatus and methodaccording to one embodiment of the invention. In the disclosedembodiment, a recipe storage MCU and flow control MCU replace the priorknown controller, and preferably communicate with a new operatorinterface. It is to be understood that the new flow control apparatusand method can be used with various injection molding machines andmolding processes known to the skilled person.

In the advanced flow control system 10 of the present embodiment, acontroller 8 includes a flow control microcontroller (MCU) 9, alsoreferred to as the main MCU. The main MCU is operative to communicate(over wired or wireless media 29) with one or more types of userinterfaces 21 including for example a voice activated interface 23, amobile (wi-fi) interface 25, and a wired interface 27. A user (humanoperator) 31 can input to the interface 21 various process parameters,such as inputs to a recipe for controlling various types of actuatorsused in the molding process. The inputs will be transmitted from theuser interface to the main flow control MCU. The flow control MCU inturn communicates (over wired or wireless media 51) with a remote recipestorage MCU 16 mounted on a mold 40 of an injection molding apparatus 41(also referred as to an injection molding machine). The mold includesone or more pins (see FIG. 6) each driven by an actuator 45 for openingand closing one or more respective mold cavities (see FIG. 6). Theactuator may be any type of known actuator, including electrical,hydraulic, or pneumatic actuators. The actuator drives a pin for openingand closing a gate (an opening into the mold cavity), and the movementof the pin may be monitored by one or more sensors or signals on/fromthe mold 40 or machine 41 for determining one or more process parameterssuch as pin position, pin velocity, or melt pressure in the cavity or ina fluid channel upstream of the cavity (e.g., manifold), or temperaturein the cavity or in a fluid channel upstream of the cavity, or the moldcycle count. The recipe, for a respective mold, is stored in the recipestorage MCU 16 which is mounted on the mold 40, and the recipe iselectronically transmitted from the recipe MCU 16 to the main MCU 9,remote from the mold, the latter of which implements computerinstructions for controlling various parameters related to the moldingprocess of the respective mold in accordance with the recipe.

In one example, the flow control (main) MCU 9 will automatically obtainor receive the recipe of process parameters (e.g., set-up information)from the remote recipe MCU 16 which is located on the mold. This allowsfor uninterrupted mold changes, namely the mold and its associatedrecipe will be read automatically by the flow control MCU 9, withoutrequiring programming of the flow control MCU. The transmitted recipedata can be implemented by executing the flow control computerinstructions stored on the flow control MCU 9. For example, the flowcontrol MCU can be used to control the velocity of the pin(s), maintainthe melt pressure at a desired melt pressure profile, and/or sequencethe pin(s) in a mold using various other inputs.

Furthermore, the flow control (main) MCU 9 receives as input(s) from themold 40 and/or machine 41 one or more electronic signals (digital oranalog), over communication channels 51, indicative of the moldingprocess, thus providing a feedback loop for one or more processparameters, e.g., for pressure control based on melt pressure and/orcavity pressure. This feedback can be provided or displayed to anoperator 31, allowing the operator to input changes to the recipe, andthe modified recipe can then be executed by the main MCU (as the newcurrent recipe).

In one embodiment, the recipe storage MCU 16 is mounted on an electricaljunction box (a container for electrical connections) which allows forcommunications between the mold 40 and the flow control MCU 9 in orderto retrieve and store recipes on the mold MCU 16. In addition tocommunicating the recipe data, the flow control MCU can interact (e.g.,via the junction box) with various optional sensors and signals on/fromthe mold and machine, such as position sensors, melt pressure sensors,cavity pressure sensors, temperature sensors, screw position and otherinjection molding machine signals to control the actuation of each pinin the mold, or the mold cycle count. FIG. 1 shows various signals,including recipe 52, position 53, melt pressure 54 and cavity pressure55, being electronically transmitted from the mold machine to the remotemain MCU 9, e.g., via wired or wireless communication channel(s).

As previously described, the user interface 21 enables a user 31 (humanoperator) to observe the tracking of the actual process parameters,versus the target (desired) process parameters, during the injectioncycle in real time, or after the cycle is complete. In one example, theinterface 21 includes an associated display 22 for tracking suchparameters. One type of display is a simple indicator panel (similar topanel 61 shown in communication with the controller 8) that tells theoperator whether the valve pin is open or closed. In this example, thecontrol system can transmit discrete signals indicating whether thevalve pin is closed or opened.

In another example, a display (such as display 71) is provided thatenables continuous position monitoring of the pin, by the user. In thisexample, the control system 8 transmits a signal to drive a displayshowing (e.g., in a graph of position versus time) the position of thevalve pin throughout the injection cycle.

The display(s) can be either local or remote with respect to the flowcontrol MCU, the user interface, and/or the mold. In one example, thepin open/closed indicator panel 61 is mounted on the injection moldingmachine 41. In another example, the graphical display 71 (of pinposition versus time) is provided on the user interface 21, such as on adisplay screen of a mobile telephone, smartphone, tablet or othercomputer device.

In one embodiment, the user interface 21 is a voice activated interface23 and includes a voice interpreter MCU 23 a. Such an interface mayutilize any of various readily available components, such as a voicerecognition chip. As the operator will typically have fairly specificand a limited range of inputs (commands), any of various commerciallyavailable voice recognition software can be used. For example, RSC-364is a single chip that combines the flexibility of a microcontroller withadvanced speech technology, including high-quality speech recognition,speech and music synthesis, speaker verification, and voice record andplayback. A product can use one or all of the RSC-364 features in asingle application. See http://www.sensoryinc.com/.

In another embodiment, the operator interface 21 is a mobile interface25, such as a WIFI interface, that can be accessed via a local wirelesshot spot. The wireless device can be any of various mobile laptops,tablets, smartphones, or other forms of computers, that can runapplications and/or a browser. In one example, a WIFI MCU 25 a receivesinput via the mobile device from the human operator 31 and communicatesparameters/commands to the flow control MCU 9. This would enable theoperator to travel around an injection molding facility or plant, whileinputting commands. Further, assuming the mobile device includes adisplay screen providing process feedback on the existing profile data,the operator can then generate and transmit changes to the recipe fromthe user interface to the mold MCU 16 (either directly or via the mainMCU 9). The modified recipe can then be stored at the mold MCU 16 as the(new) current recipe.

In a further alternative, the user interface 21 is a hardwired interface27 (including e.g., display 22 and pendent MCU 27 a as shown in FIG. 1),such as a desktop computer or computer device with an input keyboard orgraphical user interface. The one or more interfaces 23, 25, 27 can beconnected to the main MCU 9 of controller 8 via wired or wirelesscommunication channels 29.

Flow Control Method

FIG. 2 illustrates one method embodiment 200 of the invention. In step210, the current recipe stored on a recipe storage MCU located on themold, is transmitted to the remote main MCU. In the next step 212, themain MCU executes computer instructions to control the injection moldingprocess in accordance with the current recipe.

Another method embodiment 300 of the invention is illustrated in FIG. 3.In a first step 310, the current recipe is transmitted from the recipestorage MCU located on the mold to the remote main MCU and stored as the(new) current recipe. In a next step 312, the current recipe isdisplayed. In step 314, a human operator (viewing the display)determines whether changes are required to the current recipe. Ifchanges are required, then in step 316 the operator inputs changes tothe current recipe via a remote human operator interface, creating amodified recipe. Next, at step 318, the modified recipe is transmittedto the main MCU and/or recipe storage MCU and stored as the (new)current recipe. Then the method proceeds to step 320, where the main MCUexecutes computer instructions to control the injection molding processin accordance with the current (modified) recipe. Alternatively, if nochanges are required to the current recipe (at step 314), then themethod proceeds immediately to step 320 to execute the computerinstructions in accordance with the current (unmodified) recipe.

FIG. 4 illustrates another method embodiment 400 of the invention. In afirst step 410, the current recipe is transmitted from the recipestorage MCU located on the mold to the remote main MCU. In the next step412, the main MCU executes computer instructions to control theinjection molding process in accordance with the recipe. In the nextstep 414, process feedback is displayed, for example process parametersand/or molded part parameters from which the human operator candetermine whether to make changes to the recipe. In the next step 416,the human operator determines whether changes to the current recipe arerequired. If so, in the next step 418 the operator inputs changes to thecurrent recipe via a remote operator interface creating a modifiedrecipe. In the next step 420, the modified recipe is transmitted to themain MCU and/or the recipe storage MCU. In the next step 422, the mainMCU executes computer instructions to control the injection moldingprocess in accordance with the new current (modified) recipe.Alternatively, if no changes are required (at step 414), then the methodproceeds directly to step 422 to execute the computer instructions inaccordance with the current (unmodified) recipe. In an optional furtherfeedback loop, during or after step 422 the process returns to step 414to display process feedback, wherein the operator can then determine atstep 416 whether to further modify the current (or previously modified)recipe.

FIG. 5 illustrates a further method embodiment 500 of the invention. Ina first step 510, a mold is added or changed having a recipe storage MCUlocated on the mold storing the current recipe. In a next step 512, thecurrent recipe is transmitted from the recipe MCU located on the mold tothe remote main MCU. In a next step 514, the main MCU executes computerinstructions to control the injection molding process in accordance withthe current recipe. Thus, the method illustrated in FIG. 5 would allow amold operator, such as a night-shift operator, to change the moldwithout having to input which recipe to run. The control system (e.g.,of FIG. 1) will automatically identify the mold and run the currentrecipe stored on the mold without any human operator input required.

Injection Molding Apparatus and Method

FIG. 6 shows an injection molding system 1000, including a controller1016 (with a flow control MCU 9 as per FIG. 1) and a recipe storagesystem 1010 (with a recipe storage MCU 16 as per FIG. 1), the latter ofwhich is mounted on a mold 1002 according to one embodiment of theinvention. In this example, three gates feed a mold cavity as specifiedby a recipe of process parameters stored on the mold storage device 1010and transmitted via communication channel 1009 to the main MCU incontroller 1016 for execution.

A central nozzle 1022 is shown in FIG. 6 feeding molten material from aninjection molding machine 1001 through a main inlet 1018 to adistribution channel 1019 of a manifold 1039. The distribution channelcommonly feeds three separate nozzles 1020, 1022, 1024 which allcommonly feed into a common cavity 1030 of a mold 1002 to make onemolded part. A central nozzle 1022 is controlled by actuator 1940 andarranged so as to feed into cavity 1030 at an entrance point or gatethat is disposed at about the center 1032 of the cavity. As shown, apair of lateral nozzles 1020, 1024 feed into the mold cavity 1030 atgate locations that are distal 1034, 1036 to the center gate feedposition 1032.

As shown in FIGS. 6 and 6A-6E, the injection cycle is a cascade processwhere injection is effected in a sequence from the center nozzle 1022first and at a later predetermined time from the lateral nozzles 1020,1024. As shown in FIG. 6A the injection cycle is started by firstopening the pin 1040 of the center nozzle 1022 and allowing the fluidmaterial M (typically polymer or plastic material) to flow up to aposition in the cavity just before 1100 b, the distally disposedentrance into the cavity of the lateral nozzle 1024. Once the fluidmaterial has further traveled just past the entrance to nozzle 1024, atposition 1100 p, the center gate 1032 of the center nozzle 1022 istypically closed by pin 1040 as shown in FIG. 6B. The lateral gates1034, 1036 are then opened by upstream withdrawal of lateral nozzle pins1041, 1042 as shown in FIGS. 6B-6E. The rate of upstream withdrawal ortravel velocity of lateral pins 1041, 1042 is controlled as describedbelow.

In alternative embodiments, the center gate 1032 and associated actuator1940 and valve pin 1040 can remain open at, during and subsequent to thetimes that the lateral gates 1034, 1036 are opened such that fluidmaterial flows into cavity 1030 through both the center gate 1032 andone or both of the lateral gates 1034, 1036 simultaneously.

When the lateral gates 1034, 1036 are opened and fluid material NM isallowed to first enter the mold cavity into the stream M that has beeninjected from center nozzle 1022 past gates 1034, 1036, the two streamsNM and M mix with each other. If the velocity of the fluid material NMis too high, such as often occurs when the flow velocity of injectionfluid material through gates 1034, 1036 is at maximum, a visible line ordefect in the mixing of the two streams M and NM will appear in thefinal cooled molded product at the areas where gates 1034,1036 injectinto the mold cavity. By injecting NM at a reduced flow rate for arelatively short period of time at the beginning when the gates 1034,1036 are first opened and following the time when NM first enters theflow stream M, the appearance of a visible line or defect in the finalmolded product can be reduced or eliminated.

The rate or velocity of upstream withdrawal of lateral pins 1041, 1042starting from the closed position is controlled via controller 1016(FIGS. 6 and 7) which controls the rate and direction of flow ofhydraulic fluid from a drive system 1700 to actuators 1940, 1941, 1942.A “controller,” as used generally herein, refers to electrical andelectronic control apparati that comprise a single box or multiple boxes(typically interconnected and communicating with each other) thatcontain(s) all of the separate electronic processing, memory andelectrical signal generating components that are necessary or desirablefor carrying out and constructing the methods, functions and apparatusesdescribed herein. Such electronic and electrical components may includeprograms, microprocessors, computers, PID controllers, voltageregulators, current regulators, circuit boards, motors, batteries andinstructions for controlling any variable element discussed herein suchas length of time, degree of electrical signal output and the like. Forexample a component of a controller, as that term is used herein,includes programs, controllers and the like that perform functions suchas monitoring, alerting and initiating an injection molding cycleincluding a control device that is used as a standalone device forperforming conventional functions such as signaling and instructing anindividual injection valve or a series of interdependent valves to startan injection, namely move an actuator and associated valve pin from agate closed to a gate open position. In addition, although fluid drivenactuators are employed in the disclosed embodiments, actuators poweredby an electric or electronic motor or drive source can alternatively beused as the actuator component. Another embodiment would have thecontroller dynamically control the movement of an actuator andassociated valve pin in order to meet target pressure profiles basedupon (closed loop) feedback received by the controller from the pressuresensor. Yet another embodiment would have the controller trigger theopening and/or closing of an actuator and associated valve pin basedupon a sensed pressure or temperature condition within the cavity.

As shown in FIGS. 7A-7B, a supply of hydraulic fluid 1014 is fed firstthrough a directional control valve 1750 mechanism that switches thehydraulic fluid flow to the actuator cylinders in either of twodirections: fluid out to withdraw the pin upstream, FIG. 7A, and fluidin to drive the pin downstream, FIG. 7B. At the beginning of aninjection cycle the gate of a lateral valve 1034, 1036 is closed and thehydraulic system is in the directional configuration of FIG. 7B. When acycle is started, the directional configuration of the directional valve1750 of the hydraulic system 1700 is switched by controller 1016 to theconfiguration of FIG. 7A. The hydraulic system includes a flowrestriction valve 1600 that can vary the rate of flow of hydraulic fluidto the actuator 1941 under the control of the controller 1016 to varythe rate of travel, upstream or downstream of the piston of the actuator1941 which in turn controls the direction and rate of travel of pin1041. Although not shown in FIGS. 7A, 7B, the hydraulic system 1700controls the direction and rate of travel of the pistons of actuators1950 and 1952 in a manner similar to the manner of control of actuator1951 via the connections shown in FIG. 6.

The user programs controller 1016 via data inputs on a user interface toinstruct the hydraulic system 1700 to drive pins 1041, 1042 at anupstream velocity of travel that is reduced relative to a maximumvelocity that the hydraulic system can drive the pins 1041, 1042 totravel. As described below, such reduced pin withdrawal rate or velocityis executed until a position sensor such as 1951, 1952 detects that anactuator 1941, 1942 or an associated valve pin (or another component),has reached a certain position such as the end point of a restrictedflow path RP. A typical amount of time over which the pins are withdrawnat a reduced velocity is between about 0.01 and 0.10 second, the entireinjection cycle time typically being between about 0.3 seconds and about3 seconds, more typically between about 0.5 seconds and about 1.5seconds.

FIG. 6 shows position sensors 1950, 1951, 1952 for sensing the positionof their respective actuator cylinders (1940, 1941, 1942) and theirassociated valve pins (1040, 1041, 1042) and feeding such positioninformation to controller 1016 for monitoring purposes. As shown, fluidmaterial 1018 is injected from an injection machine into a manifoldrunner 1019 and further downstream into the bores 1044, 1046 of thelateral nozzles 1024, 1022 and ultimately downstream through the gates1032, 1034, 1036. When the pins 1041, 1042 are withdrawn upstream to aposition where the tip end of the pins 1041, 1042 are in a fullyupstream open FO position such as shown in FIG. 6D, the rate of flow offluid material through the gates 1034, 1036 is at a maximum. Howeverwhen the pins 1041, 1042 are initially withdrawn beginning from theclosed gate position, FIG. 6A, to intermediate upstream positions, FIGS.6B, 6C, a gap 1154, 1156 that restricts the velocity of fluid materialflow is formed between the outer surfaces 1155 of the tip end of thepins 1044, 1046 and the inner surfaces 1254, of the gate areas of thenozzles 1024, 1020. The restricted flow gap 1154, 1156 remains smallenough to restrict and reduce the rate of flow of fluid material Mthrough gates 1034, 1036 to a rate that is less than maximum flowvelocity over a travel distance RP of the tip end of the pins 1041, 1042going from closed to upstream as shown in FIGS. 6, 6B, 6C, 6E.

The trace or visible lines that appear in the body of a part that isultimately formed within the cavity of the mold on cooling above can bereduced or eliminated by reducing or controlling the velocity of the pin1041, 1042 opening or upstream withdrawal from the gate closed positionto a selected intermediate upstream gate open position that ispreferably 75% or more of the length of RP. RP can be about 1-8 mm inlength and more typically about 2-6 mm and even more typically 2-4 mm inlength. As shown in FIG. 7 in such an embodiment, a control system orcontroller 1016 is programmed to control the sequence and/or the ratesof valve pin 1040, 1041, 1042 opening and/or closing.

The velocity of withdrawal of the valve pins 1041, 1042 is determined byregulation of the flow of hydraulic drive fluid that is pumped from asupply 1014 to the actuators 1941, 1942 through a flow restrictor valve1600, FIGS. 6-7. When the flow restrictor valve 1600 is completely open,namely 100% open, allowing maximum flow of the pressurized hydraulicfluid to the actuator cylinders, the valve pins 1041, 1042 are driven ata maximum upstream travel velocity. The degree of openness of the flowrestrictor valve is adjusted in response to sensing of position of asuitable component such as an actuator 1941, 1942 or associated valvepin to less than 100% open. Adjustment of the flow restrictor valve 1600to less than 100% open thus reduces the rate and volume flow ofpressurized hydraulic fluid to the actuator cylinders thus in turnreducing the velocity of upstream travel of the pins 1041, 1042 for theselected period of time. At the end of the travel or length of path RP,a position sensor signals the controller 1016, the controller 1016determines that the end has been reached and the valve 1600 is opened toa higher velocity, typically to its 100% open position to allow theactuator pistons and the valve pins 1041, 1042 to be driven at maximumupstream velocity in order to reduce the cycle time of the injectioncycle.

The valve 1600 typically comprises a restrictor valve that iscontrollably positionable anywhere between completely closed (0% open)and completely open (100% open). Adjustment of the position of therestrictor valve 1600 is typically accomplished via a source ofelectrical power that controllably drives an electromechanical mechanismthat causes the valve to rotate such as a rotating spool that reacts toa magnetic or electromagnetic field created by the electrical signaloutput of the controller 1016, namely an output of electrical energy,electrical power, voltage, current or amperage the degree or amount ofwhich can be readily and controllably varied by conventional electricaloutput devices. The electro-mechanism is controllably drivable to causethe valve 1600 to open or close to a degree of openness that isproportional to the amount or degree of electrical energy that is inputto drive the electro-mechanism. The velocity of upstream withdrawaltravel of the pins 1041, 1042 are in turn proportional to the degree ofopenness of the valve 1600.

FIGS. 8A-8D show various examples of position sensors, the mounting andoperation of which are described in U.S. Patent Publication No.2009/0061034, the disclosure of which is incorporated herein byreference. As shown the position sensor 800 of FIGS. 8A and 8B forexample can track and signal the position of the piston of an actuatorpiston 823 continuously along its entire path of travel from which dataa pin velocity can be continuously calculated over the length of RP viaa spring loaded follower 802 that is in constant engagement with flange804 during the course of travel of piston 823. Mechanism 800 constantlysends signals to controller 1016 in real time to report the position ofpin 1041 and its associated actuator. FIGS. 8C, 8D show alternativeembodiments using position switches that detect position at specificindividual positions of the actuator and its associated valve pin 1041.The FIG. 8C embodiment uses a single trip position switch 830 a withtrip mechanism 833 that physically engages with the piston surface 823 awhen the piston 823 reaches the position of the trip mechanism 833. TheFIG. 8D embodiment shows the use of two separate position switches 830a, 830 aa having sequentially spaced trips 833 aa and 833 aaa thatreport the difference in time or distance between each trip engagingsurface 823 a of the piston, the data from which can be used bycontroller 1016 to calculate velocity of the actuator based on the timeof travel of the actuator from tripping one switch 830 a and thentripping the next 830 aa. In each embodiment the position switch cansignal the controller 1016 when the valve pin 1041, 1042 has traveled toone or more selected intermediate upstream gate open positions betweenGC (gate closed) and RP so that the velocity of the pin can be adjustedto the selected or predetermined velocities determined by the user. Ascan be readily imagined other position sensor mechanisms can be usedsuch as optical sensors, sensors that mechanically or electronicallydetect the movement of the valve pin or actuator or the movement ofanother component of the apparatus that corresponds to movement of theactuator or valve pin.

In alternative embodiments the controller can include a processor andinstructions that receive the pin position information and signals fromthe position sensor and calculate the real time velocity of the pin fromthe pin position data in real time at one or more times or positionsover the course of the pin travel through the RP path length and/orbeyond. Typically such calculations of velocity are continuousthroughout the cycle. In such an embodiment, the calculated pin velocityis constantly compared to a predetermined target profile of pinvelocities and the velocity of the pin is adjusted in real time by thecontroller 1016 to conform to the profile. In this embodiment, as in theprevious described embodiment, the pin is moved continuously upstream atall times between the gate closed position and all positions upstream ofthe gate closed position. Such control systems are described in greaterdetail in for example U.S. Patent Publication No. 2009/0061034, thedisclosure of which is incorporated herein by reference.

As discussed above, control over the velocity of pin movement in anembodiment where the pin is driven by a hydraulic or pneumatic actuatoris typically accomplished by controlling the degree of openness of thefluid restriction valve 1600, control over velocity and drive rate orposition of valve 1600 being the same functions in terms of theinstructions, processor design or computer software that carries outinstructing and implementing the velocity or drive rate adjustment tothe valve pin or actuator. Where the position sensing system senses theposition of the pin or other component multiple times throughout thecourse of the pin or other component movement, and real time velocitycan be calculated by the controller 1016, a program or instructions canbe alternatively used to receive a velocity data input by the user tothe controller 1016 as the variable to be stored and processed insteadof a predetermined voltage or current input Where an actuator thatcomprises an electric motor is used as the drive mechanism for movingthe valve pin 1041, 1042 instead of a fluid driven actuator, thecontroller 1016 can similarly be programmed to receive and processvelocity data input as a variable for controlling the velocity or rateof drive of the electric actuator.

User Interface and Target Profiles

FIG. 9 shows time versus pressure graphs (1235, 1237, 1239, 1241) of thepressure detected by four pressure transducers associated with fournozzles mounted in a manifold block. The four nozzles are substantiallysimilar to the nozzles shown in FIG. 6 and include pressure transducerscoupled to the controller 1016.

The graphs of FIGS. 9A-9D are generated on a user interface (e.g., 21,71 of FIG. 1), so that a user can observe the tracking of the actualpressure versus the target pressure during the injection cycle in realtime, or after the cycle is complete. The four different graphs of FIG.9 show four independent target pressure profiles (“desired”) emulated bythe four individual nozzles. Different target profiles are desirable touniformly fill different sized individual cavities associated with eachnozzle, or to uniformly fill different sized sections of a singlecavity. Graphs such as these can be generated with respect to any of theprevious embodiments described herein.

The valve pin associated with graph 1235 is opened sequentially at 0.5seconds after the valves associated with the other three graphs (1237,1239 and 1241) were opened at 0.00 seconds. At approximately 6.25seconds, at the end of the injection cycle, all four valve pins are backin the closed position. During injection (for example, 0.00 to 1.0seconds in FIG. 9B) and pack (for example, 1.0 to 6.25 seconds in FIG.9B) portions of the graphs, each valve pin is controlled to a pluralityof positions to alter the pressure sensed by the pressure transducerassociated therewith to track the target pressure.

Through the user interface, target profiles can be designed, and changescan be made to any of the target profiles using standard (e.g.,windows-based) editing techniques. The profiles are then used bycontroller 1016 to control the position of the valve pin. For example,FIG. 10 shows an example of a profile creation and editing screen 1300generated on a user interface.

Screen 1300 is generated by a windows-based application performed on theuser interface, e.g., any of the user interfaces 21 shown in FIG. 1.Alternatively, this screen display could be generated on an interfaceassociated with the controller (e.g., display 71 associated withcontroller 8 in FIG. 1). Interactive screen 1300 provides a user withthe ability to create a new target profile or edit an existing targetprofile for any given nozzle and cavity associated therewith.

A profile 1310 includes (x, y) data pairs, corresponding to time values1320 and pressure values 1330 which represent the desired pressuresensed by the pressure transducer for the particular nozzle beingprofiled. The screen shown in FIG. 10 is shown in a “basic” mode inwhich a limited group of parameters are entered to generate a profile.For example, in the foregoing embodiment, the “basic” mode permits auser to input start time displayed at 1340, maximum fill pressuredisplayed at 1350 (also known as injection pressure), the start of packtime displayed at 1360, the pack pressure displayed at 1370, and thetotal cycle time displayed at 1380.

The screen also allows the user to select the particular valve pin theyare controlling displayed at 1390, and name the part being moldeddisplayed at 1400. Each of these parameters can be adjustedindependently using standard windows-based editing techniques such asusing a cursor to actuate up/down arrows 1410, or by simply typing invalues on a keyboard. As these parameters are entered and modified, theprofile will be displayed on a graph 1420 according to the parametersselected at that time.

By clicking on a pull-down menu arrow 1391, the user can selectdifferent nozzle valves in order to create, view or edit a profile forthe selected nozzle valve and cavity associated therewith. Also, a partname 1400 can be entered and displayed for each selected nozzle valve.

The newly edited profile can be saved in computer memory individually,or saved as a group of profiles for a group of nozzles that inject intoa particular single or multi-cavity mold. The term “recipe” is used todescribe one or more of profiles for a particular mold and the name ofthe particular recipe is displayed at 1430 on the screen icon.

To create a new profile or edit an existing profile, first the userselects a particular nozzle valve of the group of valves for theparticular recipe group being profiled. The valve selection is displayedat 1390. The user inputs an alpha/numeric name to be associated with theprofile being created, for family tool molds this may be called a partname displayed at 1400. The user then inputs a time displayed at 1340 tospecify when injection starts. A delay can be with particular valve pinsto sequence the opening of the valve pins and the injection of meltmaterial into different gates of a mold.

The user then inputs the fill (injection) pressure displayed at 1350. Inthe basic mode, the ramp from zero pressure to max fill pressure is afixed time, for example, 0.3 seconds. The user next inputs the startpack time to indicate when the pack phase of the injection cycle starts.The ramp from the filling phase to the packing phase is also fixed timein the basic mode, for example, 0.3 seconds.

The final parameter is the cycle time which is displayed at 1380 inwhich the user specifies when the pack phase (and the injection cycle)ends. The ramp from the pack phase to zero pressure may be instantaneouswhen a valve pin is used to close the gate, or slower in a thermal gatedue to the residual pressure in the cavity which will decay to zeropressure once the part solidifies in the mold cavity.

User input buttons 1415 through 1455 are used to save and load targetprofiles. Button 1415 permits the user to close the screen. When thisbutton is clicked, the current group of profiles will take effect forthe recipe being profiled. Cancel button 1425 is used to ignore currentprofile changes and revert back to the original profiles and close thescreen. Read Trace button 1435 is used to load an existing and savedtarget profile from memory. The profiles can be stored in memorycontained in one or more of the operator interface 21, the main MCU 9,and the recipe storage MCU 16. Save trace button 1440 is used to savethe current profile. Read group button 1445 is used to load an existingrecipe group. Save group button 1450 is used to save the current groupof target profiles for a group of nozzle valve pins. The process tuningbutton 1455 allows the user to change the settings (for example, thegains) for a particular nozzle valve in a control zone. Also displayedis a pressure range 1465 for the injection molding application.

While specific embodiments of the present invention have been shown anddescribed, it will be apparent that many modifications can be madethereto without departing from the scope of the invention. For example,in one embodiment the controller is mounted on a hydraulic power unit.In one embodiment, the flow control MCU receives, displays and/orrecords a signal from an electronic mold counting sensor for correlatingdetected pin motion data to the recipe data for a given molding cycle.In one embodiment, the system includes a plurality of flow control MCU'seach controlling a corresponding one of a plurality of pins. In oneembodiment, the flow control MCU transmits signals to an electric motorfor controlling one or more of pin position and rate of pin movement. Inone embodiment, both the recipe MCU and the flow control MCU are mountedto the mold. In one embodiment, the controller is contained in aphysical box which is mounted to the injection machine and/or placednear the injection machine. In one embodiment, the controller associates(compares) the recipe data to data collected during one injection cycle.In one embodiment, each valve pin has its own profile per injectioncycle, and the recipe is a collection of such profiles for a pluralityof pins.

In one embodiment, a mold having no recipe or a non-approved (notcurrent or previously tested) recipe stored in the recipe storage MCU,is mounted to the machine. An operator can then create a recipe bytesting different inputs to the controller, e.g., adjusting the rate ofspeed and/or position of one or more pins. When the user is satisfiedwith the parts being produced in the mold or with data and/or signalsreceived from the mold (e.g., temperature and/or pressure), the operatorthen stores a copy of the newly created recipe by transmitting (director indirectly) the new recipe for storage on the recipe storage MCU. Themain MCU of the controller stores a local copy of the new recipe, andruns the recipe (executes instructions implementing the recipe) for themold. Then later, if this first mold is removed and a new mold ismounted to the machine, where the new mold has a proper recipe alreadystored on the new mold MCU, the controller can then immediately run thenew recipe for the new mold on the machine. If not, the operator canagain create a new recipe for the new mold, as previously described.

The recipe data typically comprises a profile of values of a conditionof the injected polymer material or a condition or position of aselected component of the injection molding apparatus that is specifiedto occur at each point in time over the course or duration of aninjection cycle when a part is produced in the mold cavity. Thus aprofile defines a set of conditions, events or positions to which theinjection material or the component of the apparatus is adjusted toattain over the course of a particular injection cycle. Typicalinjection material conditions that can be specified and controlled arepressure of the injection material at selected positions within a flowchannel of the manifold, within an injection nozzle or within the moldcavity. Typical conditions or positions of components of the apparatusthat can be controlled and comprise a profile are the position of thevalve pin, the position of the screw of the barrel of the injectionmolding machine and position of an actuator piston. Such profiles andrecipes are disclosed in detail in for example U.S. Pat. No. 6,464,909and U.S. Pat. No. 8,016,581 and U.S. Pat. No. 7,597,828, the disclosuresof which are incorporated by reference as if fully set forth herein.

Various other embodiments will be apparent to the skilled person.Accordingly, the invention is not limited by the foregoing embodiments.

What is claimed is:
 1. A method of performing an injection molding cyclein an injection molding apparatus comprising a manifold that receives aninjection fluid, the manifold distributing injection fluid to a fluiddelivery channel that delivers the injection fluid under an injectionpressure to a gate of a mold cavity and a valve pin having an axis and atip end, the valve pin being slidably mounted for movement along theaxis within the fluid delivery channel, the method comprising: drivablyinterconnecting the valve pin to an actuator in an arrangement whereinthe actuator drives the valve pin upstream and downstream along the axisand drives the tip end of the valve pin upstream and downstream betweena first closed position where the tip end of the valve pin obstructs thegate to prevent the injection fluid from flowing into the cavity, a fullopen position where the injection fluid material flows freely withoutrestriction from the tip end of the pin through the gate, and one ormore intermediate positions between the first position and the full openposition wherein the tip end of the valve pin restricts flow of theinjection fluid along at least a portion of the length of the drive pathextending between the first closed position and the intermediateposition, and, controllably operating the actuator to drive the valvepin to be disposed or held in a selected intermediate position for aselected period of time during the course of an injection cycle wherethe tip end of the valve pin restricts flow of injection fluid throughthe gate to the mold cavity.
 2. The method of claim 1 further comprisingcontrollably operating the actuator to drive the valve pin downstreambeginning from the full open position to the selected intermediateposition, holding the valve pin in the selected intermediate positionfor the selected period of time, and subsequently driving the valve pindownstream from the intermediate position to the first closed position.3. The method of claim 2 further comprising controllably operating theactuator to drive the valve pin downstream beginning from the full openposition at a high rate of downstream travel, subsequently driving thevalve pin downstream at one or more intermediate rates of downstreamtravel to the selected intermediate position, subsequently holding thevalve pin in the selected intermediate position for the selected periodof time and subsequently driving the valve pin downstream from theselected intermediate position to the first closed position.
 4. Themethod of claim 1 further comprising controllably operating the actuatorto drive the valve pin upstream beginning from the first closed positionto the selected intermediate position, holding the valve pin in theselected intermediate position for the selected period of time, andsubsequently driving the valve pin upstream from the intermediateposition to the full open position.
 5. The method of claim 4 furthercomprising controllably operating the actuator to drive the valve pinupstream beginning from the first closed position at a reduced rate ofupstream travel, subsequently holding the valve pin in the selectedintermediate position and subsequently driving the valve pin upstreamfrom the intermediate position to the full open position at a high rateof upstream travel greater than the reduced rate of upstream travel. 6.The method of claim 1 wherein the actuator comprises an electricallypowered motor or electric motor.
 7. The method of claim 1 wherein theselected intermediate position in which the valve pin is disposed orheld is a position at which pressure of the injection fluid is a packpressure.
 8. An injection molding apparatus comprising a manifold thatreceives an injection fluid from an injection molding machine, themanifold distributing the injection fluid to a fluid delivery channelthat delivers the injection fluid under an injection pressure to a gateof a mold cavity and a valve pin having an axis and a tip end, the valvepin being slidably mounted for movement along the axis within the fluiddelivery channel, wherein the valve pin is interconnected to an actuatorin an arrangement wherein the actuator is adapted to drive the valve pinupstream and downstream along the axis and to drive the tip end of thevalve pin upstream and downstream between a first closed position wherethe tip end of the valve pin obstructs the gate to prevent the injectionfluid from flowing into the cavity, a full open position where theinjection fluid material flows freely without restriction from the tipend of the pin through the gate, and one or more intermediate positionsbetween the first position and the full open position wherein the tipend of the valve pin restricts flow of the injection fluid along atleast a portion of the length of the drive path extending between thefirst closed position and the intermediate position, the apparatusincluding a controller that contains instructions that instruct theactuator to controllably drive the valve pin to be disposed or held in aselected intermediate position for a selected period of time during thecourse of an injection cycle where the tip end of the valve pinrestricts flow of injection fluid through the gate to the mold cavity.9. The apparatus of claim 8 wherein the controller includes instructionsthat instruct the actuator to drive the valve pin downstream beginningfrom the full open position to the selected intermediate position, tohold the valve pin in the selected intermediate position for theselected period of time, and to subsequently drive the valve pindownstream from the intermediate position to the first closed position.10. The apparatus of claim 9 wherein the controller includesinstructions that instruct the actuator to drive the valve pindownstream beginning from the full open position at a high rate ofdownstream travel, to subsequently drive the valve pin downstream at oneor more of the intermediate rates of downstream travel the selectedintermediate position, to subsequently hold the valve pin in theselected intermediate position for the selected period of time and tosubsequently drive the valve pin downstream from the selectedintermediate position to the first closed position.
 11. The apparatus ofclaim 8 wherein the controller includes instructions that instruct theactuator to controllably drive the valve pin upstream beginning from thefirst closed position to the selected intermediate position, to hold thevalve pin in the selected intermediate position for the selected periodof time, and to subsequently drive the valve pin upstream from theintermediate position to the full open position.
 12. The apparatus ofclaim 11 wherein the controller includes instructions that instruct theactuator to drive the valve pin upstream beginning from the first closedposition at a reduced rate of upstream travel, to subsequently hold thevalve pin in the selected intermediate position for the selected periodof time and to subsequently drive the valve pin upstream from theintermediate position to the full open position at a high rate ofupstream travel greater than the reduced rate of upstream travel. 13.The apparatus of claim 8 wherein the actuator comprises an electricallypowered motor or electric motor.
 14. A method of performing an injectionmolding cycle in an injection molding apparatus comprising a manifoldthat receives an injection fluid, the manifold distributing injectionfluid to a fluid delivery channel that delivers the injection fluidunder an injection pressure to a gate of a mold cavity and a valve pinhaving an axis and a tip end, the valve pin being slidably mounted formovement along the axis within the fluid delivery channel, the methodcomprising: drivably interconnecting the valve pin to an actuator in anarrangement wherein the actuator drives the valve pin upstream anddownstream along the axis and drives the tip end of the valve pinupstream and downstream between a first closed position where the tipend of the valve pin obstructs the gate to prevent the injection fluidfrom flowing into the cavity, a full open position where the injectionfluid material flows freely without restriction from the tip end of thepin through the gate, and one or more intermediate positions between thefirst position and the full open position wherein the tip end of thevalve pin restricts flow of the injection fluid along at least a portionof the length of the drive path extending between the first closedposition and the intermediate position, and, controllably operating theactuator to drive the valve pin upstream beginning from the firstposition at a reduced rate of upstream travel relative to a selectedhigh rate of upstream travel and subsequently holding the valve pin inthe selected intermediate position for a selected period of time. 15.The method of claim 14 further comprising subsequently driving the valvepin upstream from the selected intermediate position to the full openposition at the selected high rate of upstream travel.
 16. The method ofclaim 14 further comprising controllably operating the actuator to drivethe valve pin downstream beginning from the full open position at aselected high rate of downstream travel, subsequently driving the valvepin downstream at one or more intermediate rates of downstream travelthat are less than the selected high rate of downstream travel.
 17. Themethod of claim 14 wherein the high rate of upstream travel is a maximumrate of upstream travel.
 18. The method of claim 14 wherein the actuatorcomprises an electrically powered motor or electric motor.
 19. Themethod of claim 14 wherein the selected intermediate position in whichthe valve pin is disposed or held is a position at which pressure of theinjection fluid is a pack pressure.
 20. An injection molding apparatuscomprising a manifold that receives an injection fluid from an injectionmolding machine, the manifold distributing the injection fluid to afluid delivery channel that delivers the injection fluid under aninjection pressure to a gate of a mold cavity and a valve pin having anaxis and a tip end, the valve pin being slidably mounted for movementalong the axis within the fluid delivery channel, wherein the valve pinis interconnected to an actuator in an arrangement wherein the actuatoris adapted to drive the valve pin upstream and downstream along the axisand to drive the tip end of the valve pin upstream and downstreambetween a first closed position where the tip end of the valve pinobstructs the gate to prevent the injection fluid from flowing into thecavity, a full open position where the injection fluid material flowsfreely without restriction from the tip end of the pin through the gate,and one or more intermediate positions between the first position andthe full open position wherein the tip end of the valve pin restrictsflow of the injection fluid along at least a portion of the length ofthe drive path extending between the first closed position and the oneor more intermediate positions, the apparatus including a controllerthat contains instructions that instruct the actuator to controllablydrive the valve pin upstream beginning from the first closed position ata reduced rate of upstream travel relative to a high rate of upstreamtravel to a selected intermediate position and to hold the valve pin inthe selected intermediate position for a selected period of time.
 22. Amethod of performing an injection molding cycle in an injection moldingapparatus comprising a manifold that receives an injection fluid, themanifold distributing injection fluid to a fluid delivery channel thatdelivers the injection fluid under an injection pressure to a gate of amold cavity and a valve pin having an axis and a tip end, the valve pinbeing slidably mounted for movement along the axis within the fluiddelivery channel, the method comprising: drivably interconnecting thevalve pin to an actuator in an arrangement wherein the actuator drivesthe valve pin upstream and downstream along the axis and drives the tipend of the valve pin upstream and downstream between a first closedposition where the tip end of the valve pin obstructs the gate toprevent the injection fluid from flowing into the cavity, a full openposition where the injection fluid material flows freely withoutrestriction from the tip end of the pin through the gate at a maximumpressure, and an intermediate position between the first position andthe full open position wherein the tip end of the valve pin restrictsflow of the injection fluid along at least a portion of the length ofthe drive path extending between the first closed position and theintermediate position and where the injection fluid flows through thegate at a reduced pressure relative to the maximum pressure, and,controllably operating the actuator to drive the valve pin to bedisposed or held in a selected intermediate position for a selectedperiod of time during the course of an injection cycle such that thepressure of the injection fluid is held at a selected reduced pressurerelative to the maximum pressure for the selected period of time.
 23. Amethod of performing an injection molding cycle in an injection moldingapparatus comprising a manifold that receives an injection fluid, themanifold distributing injection fluid to a fluid delivery channel of anozzle that delivers the injection fluid under an injection pressure toa gate of a mold cavity and a valve pin having an axis and a tip end,the valve pin being slidably mounted for movement along the axis withinthe fluid delivery channel, the method comprising: drivablyinterconnecting the valve pin to an actuator in an arrangement whereinthe actuator drives the valve pin upstream and downstream along the axisand drives the tip end of the valve pin upstream and downstream betweena first closed position where the tip end of the valve pin obstructs thegate to prevent the injection fluid from flowing into the cavity and afull open position where the injection fluid material flows freelywithout restriction from the tip end of the pin through the gate at amaximum pressure, wherein pressure of the injection fluid associatedwith the nozzle varies between zero at the beginning of the injectioncycle when the valve pin is in the first closed position and the maximumpressure, the position of the valve pin between the first closedposition and the full open position being controllably variable to varythe pressure of the injection fluid, the method further comprisingcontrollably operating the actuator to drive the valve pin to bedisposed or held in a position intermediate the closed position and thefull open position for a selected period of time during the course of aninjection cycle where the pressure of the injection fluid is held at aselected reduced pressure relative to the maximum pressure.
 24. Themethod of claim 23 wherein the actuator comprises an electricallypowered motor or electric motor.
 25. The method of claim 23 wherein theselected intermediate position in which the valve pin is disposed orheld is a position at which pressure of the injection fluid is a packpressure.
 26. An injection molding apparatus for performing an injectioncycle comprising a manifold that receives an injection fluid, themanifold distributing injection fluid to a fluid delivery channel of anozzle that delivers the injection fluid under an injection pressure toa gate of a mold cavity and a valve pin having an axis and a tip end,the valve pin being slidably mounted for movement along the axis withinthe fluid delivery channel, the method comprising: the valve pin beingdrivably interconnected to an actuator in an arrangement wherein theactuator drives the valve pin upstream and downstream along the axis anddrives the tip end of the valve pin upstream and downstream between afirst closed position where the tip end of the valve pin obstructs thegate to prevent the injection fluid from flowing into the cavity and afull open position where the injection fluid material flows freelywithout restriction from the tip end of the pin through the gate at amaximum pressure, wherein pressure of the injection fluid associatedwith the nozzle varies between zero at the beginning of the injectioncycle when the valve pin is in the first closed position and the maximumpressure, the position of the valve pin between the first closedposition and the full open position being controllably variable to varythe pressure of the injection fluid, a controller including a set ofinstructions that instruct the actuator to controllably drive the valvepin to be disposed or held in a position intermediate the closedposition and the full open position for a selected period of time duringthe course of an injection cycle such that the pressure of the injectionfluid is held at a selected reduced pressure relative to the maximumpressure for the selected period of time.
 27. The apparatus of claim 26wherein the actuator comprises an electrically powered motor or electricmotor.
 28. The apparatus of claim 26 wherein control of the position ofthe actuator is controlled by a controller receiving signals from aposition sensor or a pressure sensor.
 29. A method of performing aninjection molding cycle in an injection molding apparatus comprising amanifold that receives an injection fluid, the manifold distributinginjection fluid to a fluid delivery channel of a nozzle that deliversthe injection fluid under an pressure to a gate of a mold cavity and avalve pin having an axis and a tip end, the valve pin being slidablymounted for movement along the axis within the fluid delivery channel,the method comprising: drivably interconnecting the valve pin to anactuator in an arrangement wherein the actuator drives the valve pinupstream and downstream along the axis and drives the tip end of thevalve pin upstream and downstream between a first closed position wherethe tip end of the valve pin obstructs the gate to prevent the injectionfluid from flowing into the cavity, a fill or injection pressureposition where the injection fluid material flows through the gate at aselected high pressure and one or more pack pressure positions betweenthe first closed position and the fill or injection pressure position,wherein pressure of the injection fluid associated with the nozzle inthe pack pressure position is greater than a zero pressure when thevalve pin is in the first closed position and less than a selected highpressure when the valve pin is in the fill or injection pressureposition, the position of the valve pin between the first closedposition and the fill or injection pressure position being controllablyvariable to vary the pressure of the injection fluid, the method furthercomprising controllably operating the actuator to drive the valve pinduring the course of an injection cycle to first move from the firstclosed position to the fill or injection pressure position, tosubsequently move from the fill or injection pressure position to bedisposed and maintained in a pack pressure position for a selectedperiod of time and to subsequently move from the pack pressure positionto the first closed position.
 30. The method of claim 29 wherein thevalve pin is controllably movable between the first closed position andfill or injection pressure position at one or more selectively variablevelocities.
 31. The method of claim 29 wherein the valve pin iscontrollably movable between the fill or injection pressure position andthe pack pressure position at one or more selectively variablevelocities.
 32. The method of claim 29 wherein the valve pin iscontrollably movable between the pack pressure position and the firstclosed position at one or more selectively variable velocities.
 33. Aninjection molding apparatus for performing an injection molding cyclecomprising an injection molding machine that injects an injection fluidto a manifold, the manifold distributing injection fluid to a fluiddelivery channel of a nozzle that delivers the injection fluid under anpressure to a gate of a mold cavity and a valve pin having an axis and atip end, the valve pin being slidably mounted for movement along theaxis within the fluid delivery channel, the method comprising: anactuator drivably interconnected to a valve pin in an arrangementwherein the actuator drives the valve pin upstream and downstream alongthe axis and drives the tip end of the valve pin upstream and downstreambetween a first closed position where the tip end of the valve pinobstructs the gate to prevent the injection fluid from flowing into thecavity, a fill or injection pressure position where the injection fluidmaterial flows through the gate at a selected high pressure and one ormore pack pressure positions between the first closed position and thefill or injection pressure position, wherein pressure of the injectionfluid associated with the nozzle in the pack pressure position isgreater than a zero pressure when the valve pin is in the first closedposition and less than a selected high pressure when the valve pin is inthe fill or injection pressure position, the position of the valve pinbetween the first closed position and the fill or injection pressureposition being controllably variable to vary the pressure of theinjection fluid, a controller including instructions that controllablyoperate the actuator to drive the valve pin during the course of aninjection cycle to first move from the first closed position to the fillor injection pressure position, to subsequently move from the fill orinjection pressure position to be disposed and maintained in a packpressure position for a selected period of time and to subsequently movefrom the pack pressure position to the first closed position.
 34. Theapparatus of claim 33 wherein the controller includes instructions thatcontrollably move the valve pin between the first closed position andfill or injection pressure position at one or more selectively variablevelocities.
 35. The apparatus of claim 33 wherein the controllerincludes instructions that controllably move the valve pin between thefill or injection pressure position and the pack pressure position atone or more selectively variable velocities.
 36. The apparatus of claim33 wherein the controller includes instructions that controllably movethe valve pin between the pack pressure position and the first closedposition at one or more selectively variable velocities.
 38. Theapparatus of claim 33 wherein the controller includes instructions thatcontrollably move the valve pin from the first closed position to bedisposed and maintained in the fill or injection pressure position for aselected period of time.
 39. A method of performing an injection moldingcycle in an injection molding apparatus comprising a manifold thatreceives an injection fluid, the manifold distributing injection fluidto a fluid delivery channel of a nozzle that delivers the injectionfluid under an pressure to a gate of a mold cavity and a valve pinhaving an axis and a tip end, the valve pin being slidably mounted formovement along the axis within the fluid delivery channel, the methodcomprising: drivably interconnecting the valve pin to an actuator in anarrangement wherein the actuator drives the valve pin upstream anddownstream along the axis and drives the tip end of the valve pinupstream and downstream between a first closed position where the tipend of the valve pin obstructs the gate to prevent the injection fluidfrom flowing into the cavity and one or more pack pressure positions,wherein pressure of the injection fluid associated with the nozzle inthe pack pressure position is greater than a zero pressure when thevalve pin is in the first closed position, the method further comprisingcontrollably operating the actuator to drive the valve pin during thecourse of an injection cycle to first move from the first closedposition to be disposed and maintained in a pack pressure position for aselected period of time and to subsequently move from the pack pressureposition to the first closed position.
 40. The method of claim 39wherein the valve pin is controllably movable between the first closedposition and the pack pressure position at one or more selectivelyvariable velocities.
 41. The method of claim 39 wherein the valve pin iscontrollably movable between the pack pressure position and the firstclosed position at one or more selectively variable velocities.
 42. Aninjection molding apparatus for performing an injection molding cyclecomprising an injection molding machine that injects an injection fluidto a manifold that receives an injection fluid, the manifolddistributing injection fluid to a fluid delivery channel of a nozzlethat delivers the injection fluid under an pressure to a gate of a moldcavity and a valve pin having an axis and a tip end, the valve pin beingslidably mounted for movement along the axis within the fluid deliverychannel, the method comprising: an actuator drivably interconnected to avalve pin in an arrangement wherein the actuator drives the valve pinupstream and downstream along the axis and drives the tip end of thevalve pin upstream and downstream between a first closed position wherethe tip end of the valve pin obstructs the gate to prevent the injectionfluid from flowing into the cavity and one or more pack pressurepositions, wherein pressure of the injection fluid associated with thenozzle in the pack pressure position is greater than a zero pressurewhen the valve pin is in the first closed position, a controller thatincludes instructions that controllably operate the actuator to drivethe valve pin during the course of an injection cycle to first move thevalve pin from the first closed position to be disposed and maintainedin a pack pressure position for a selected period of time and tosubsequently move from the pack pressure position to the first closedposition.
 43. The apparatus of claim 42 wherein the controller includesinstructions that controllably move the valve pin between the firstclosed position and the pack pressure position at one or moreselectively variable velocities.
 44. The apparatus of claim 42 whereinthe controller includes instructions that controllably move the valvepin between the pack pressure position and the first closed position atone or more selectively variable velocities.